Fluid-pressure brake



Jan. 31, 1928. 1,657,526

J. M. DAPRON FLUID PRESSURE BRAKE Filed April 12. 1927 -INVENTOR JOSEPHM.DAFRON ATTORN Patented Jan. 31, 1928.

UNITED STATES PATENT OFFICE.

JOSEPH M. DAPRON, OF ST. LOUIS, MISSOURI, ASSIGNORTO W'ESTENGHOUSE AIRBRAKE CODIPANY, 0F WILMERDING, PENNSYLVANIA, ACGRIPORA'IION 0F PENN- SYLVAN IA.

FLUID-PRESSUBE BRAKE.

Application filed April 12, 1927. Serial No. 183,070.

This invention relates to fluid pressure brakes, and more particularlyto a brake equipment of the type known as the safety car controlequipment.

An object 01"- the invention is to'provide a safety car controlequipment with means for varying the braking power according to the loadon the car, and in which the parts of the usual safety car control equipment are utilized without alterationyto control the'variable loadbraking means.

Anotherobject of the invention is to provide means for varying the.brakingfpower according to the load on the car and associated with'asafety car control equipment in such a manner that the variable loadbraking means is effective to vary the braking power according to theload on the car when an emergency application of the brakes is made.

Other object-sand advantages will appear from the following moredetailed descrip tion of the invention.

In the accompanying drawing, the single figure illustrates, indiagrammatic form, a fluid pressure brake of the safety car controltype, embodying the invention.

A safety car control. equipment of the usual type is shown in thedrawing,comprising in general an emergency valve devicell, a brake valvedevice 2, a safety car controller handle device 3, a door engine i, acircuit breaker cylinder device 5, a brake cylinder 6, a main reservoir7, and a sanding reservoir 8. According to my invention there isassociated wit-h this'safety carcontrol equipment, a variable load brakemechanism 9 and a relay valve device 10.

The emergency valve device 1 comprises a casing having a piston chamber11 connected to the emergency brake pipe 12 and containing a piston 13.This devicealsohas a valve chamber 141 containing a slide valve 15adapted to be operated by the piston 13. The chambers 11 and 14- areboth connected with the main reservoir 7 through the pipe 16. A relayvalve piston 17 is associated with the emergency valve device and hasthe piston chamber 18, at one side, connected through a passage 19 andpipe 20, with the safety" car controller handle device 3. The oppos teside at this relay valve is connected through a passage 21 and pipe'22to the circuit breaker cylinder device 5. u

The variableloadmechanism 9 may be of thevcharacter shown in UnitedStates Letters Patent No. 1,505,950 of Clyde C. Farmer, dated August 26,192%,and is for the purposeoi' automatically regulating the n1aximumbrake cylinder pressure, in either a service or an emergency applicationof the brakes, as the load on the car 1s mcreased ior decrease-d. Asthisirnechanism is "fully described in the above mentioned patent,'adetailed description thereof is deemed unnecessary. As in theconstruction shown in the patent, the pipe 16 is the pipe through whichcfluid under pressure from the main reservoir :7 is supplied tothevariable load mechanism to effect an emergency application of thebrakes, the pipe 23 is the pipe leading to thebrakecylin'der'G,pipe-24.is

the pipethrough which fluid under pressure is supplied to the variableload mechanism to effect a service application ofthe brakes, and lame 25is the emergency pipe. The pipe '24 and straightair service pipe 24 areadapted to be connected throughpassagesin the emergency valvedevice 1,by the slide valve 15. A i

The relay valve devicelO may comprise a casing containing a flexiblediaphragm 26 having the chamber 27 at one side connected to a pipe 28connecting with the usual sand pipe 29 and having a chamber 30 at theopposite side openfto the atmosphere. A valve'31,movable with thediaphragm 26, controls communication from chamber 30 to a chamber 32which is connected to the pipe 25, there being a check valve 33 in"thejpipe. The relay valve de vice is also provided with a valve chamber3% connected to the main reservoir pipe 16 and containing a valve whichcontrols communication 'from this chamber to the chamber32; The valves31 and35 are provided with valve stems adapted to engage so that themovement oi the diaphragm 26,

main reservoir pipe 1C and the pipe ill) or to vent the pipe :30 to theatmosphere.

Assuming); the en'iergenq valve device 1 to he in normal releaseposition, and brake valve device 2 to be in release position, as shown.in the drawing, the brake cylinder is rented to the atnmsphere in theusual manner, through the straight air pipe and the exhaust pipe 35% ofthe brake valve de vice, and the sundin reservoir is cl'iarged vvithfluid under pro re from the chamber 1% in the emergency valve device,which chamber is connected with the main reservoir.

When it is desired to make an emergency application of the brakes thebrake valve is moved to its emergency position, which causes theemergency pipe 12 and piston chamber 11 of the emergency valve device 1to he vented, through the exhaust pipe 38, to the atmosphere, so thatthe fluid under pressure in the chamber 14; o l the emergency valvedevice will cause the piston 13 to shitt the slide valve 15 to itsemergency position, when such valve will connect the sanding reservoirto the chamber 27 of the relay valve device 10. The fluid under pressurefrom the sanding reservoir nowfiows into the chamber 27 of the relayvalve device and forces the diaphragm 26. valve stems, and valves 31 anc85 downwardly. causing the valve 31 to seat and close communicationbetween the chambers 30 and 32, and-at the same time causing the valve35 to be unseated, thus permitting fluid from the main reservoir to flowinto the chamber 32 and through the, check valve 33and pipe to thevariable load mechanism 9. As described in the previously mentionedPatentv No. 1.505.950, fluid under pressure supplied through theemergency pipe to the variable load brake 1116Cl1t111l$1l1 then causesthe operation of same, so that fluid under pressure is supplied to thebrake cylinder by way of pipe 23. as limited according to the load onthe car.

As the sanding reservoir 8 is also connected to the sand pipe 29. thefluid under pressure from this? reservoir will escape through the usualsand traps (not shown) whielnattcr a time. reduces the pressure in theswirling: reservoir and Chamber 27 in the relay *alve device to such adegree that the atmosphere. The check valve till is adapted to preventthe lion ol lluid through the pipe 25, in a direction opposite to thatindicated by the arrow in the drawing. so that when the valve ill isopen. the lluid under pressure in the brake evlinder (3 cannot bemrbausted lo ll l atuurrphrre through the elnunhers l2 and ot the relayvalve device which would result in the release 0! the brakes.

Flhould the operator remove his hand l'rom the coiitroller handle of thedevice ill. the valve 37' will be moved upwardly and will. permit thefluid under prcssiu'c in the chumbcr 18 at one side of the valve piston1? ol the emergency valve device to exhaust to the atinospl'lcre throughpass re 1.) and pipe i 30. Fluid under pressure acti. r: on the outerseated area of valve piston l? as supplied thereto from the m'nergcncvbrake pipe l2 through passagm 39 in, the vu'nu'gcmrv valve device. will.now cause the valve piston l? to move to its open position, pcru'utting'fluid under pressure to llovv from passage and the emergency brake pipe12 through th pa age 21 and pipe to the circuit hrliuiluu' cylinderdevice 55. cruising the piston thcreol' to be operated to open the powercircuit in the usual manner. hen this nation has moved a predetermineddistance apertures 40 in the cvlinder ol: the device will be uncovered,which will permitlluid under pressure from the piston chamber 11 o1 theeniergency valve device to exhaust therethrouah to the atmosphere. whichrcsljl'lts in the emergency valve device piston and slide alve movingtotheir emergency prwitions.

after which the (u ieratious ol the several parts 01 the apparatus arethe same as hereinl are described.

It for any reason the relajv valve device lfl should tail to 'luncl-iouwhen an onlcre'eucv applical ion oi the brakes is desired. a serviceapplicatitm will result. due to the lluid under pressure lrom thechamber l-lot the enuu gencvvalve device flowing: into the variable load.meclninisnl through the pipe hen it is desired to malcc a serviceapplication of the brakes. the braluvalve is moved to its servicepositirun thus eminenting the main reservoir pipe ill with the servicepipe 2%. lVitb the piston Ill and slide valve 15 in their normallll'lt'illlllllF. as shown in the drawing. the pipe 2-!" willluconnectcd through the (Ellltlllfllltft valve d vice T1, slide valve 15and pipe Ell lo the rariablc load mechanism 0. thus purmilliiu: fluidfrom the main reservoir to lloivlo the mechanism. As described in theprmriouslv mentioned Patent No. 1.505.950, fluid under pressure supplicdthrough the service pipe to the variable load n'icchanisln then causesthe operation of same. so that fluid under pressure, supplied to thebrake cylinder by the way of pipe 23 limited according lo the load onthe car.

ion

news-ac As I believe I am the first to combine a variable load devicewith a safety car control equipmentflin such a manner that an emergencyapplication of the brakes, proportional to the load on the car, may bemade, I do not wish to be limited to the specific details andarrangement of the several parts of the invention shown and describedherein.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent, is:

l. The combination with a safety car control equipment, of meanscooperating therewith for causing an emergency applica tion o f thebrake proportionate to the load on the car.

2. The combination with a safety car control equipment, of a variableload mechanism associated with said equipment, and a relay valve devicelfor controlling the flow of fl'uid under pressure to said mechanism.

S. The combination with a safety car control equipment, or a variableload mechanism associated with said equipment, and a relay valve deviceincluding a valve for controlling the flow of fluid under pressure tosaid mechanism.

4t. The combination With a safety car control equipment, of a variableload mechanism associated with said equipment, a relay valve device forcontrolling the flow of fluid under pressure to said mechanism, andmeans interposed between said variable load mechanism and relay valvedevice for preventing a return flow of said fluid.

5. In a fluid pressure brake, the combination with a brake pipe, of areservoir, a variable load mechanism operable by fluid under pressure, afluid pressure operated relay valve device for supplying fluid underpressure to said variable load mechanism, and an emergency valve deviceoperated upon a reduction in brake pipe pressure for supplying fluidunder pressure from said reservoir to said relay valve device.

6. In a fluid pressure brake, the combination with a brake pipe and abrake cylinder. of a variable load brake mechanism operated by fluidunder pressure in eflecting an emergency application of the brakes forsupplying fluid under pressure to the brake cylinder according to theload on the car, a relay valve device for controlling the supply offluid under pressure to said variable load mechanism in an emergencyapplication of the brakes, and a valve device operated upon a reductionin brake pipe pressure for eflecting the operation of said relay valvedevice.

7. In a fluid pressure brake, the combination with a brake pipe and abrake cylinder, of a variable load brake mechanism operated by fluidunder pressure in effecting a service application of the brakes forsupplying ffluid :under pressureto the brake cylin der according to theload on the car and operated byfluid underpressure 1n eflecting anemergency application of the brakes for supplying fluid under pressureto the brake cylinder according to theload on the car, a

relay valve device for controlling the sup ply ol fluid underpressure tosaid variable 'loadmechanism in an emergency application of the'brakes,and a valve-device opcri able by lluidi under pressure for eflecting anapplicationot: the brakes varying in accordance with the load cont-hecar, of a relay "valve device for *supplymgfluid under pres.-

sure to said variable load mechanismyand means operable only uponeffecting an emergency application of the brakes for operating saidrelay valve device.

9. In a fluid pressure brake, the combination with a brake pipe, of asanding reservoir, a variable load mechanism operable by fluid underpressure, a relay valve device for supplying fluid under pressure tosaid variable load mechanism, said relay valve device including a valve,and means operated upon a reduction in brake pipe pressure for supplyingfluid under pressure from said reservoir to said relay valve device tooperate said valve.

10. In a fluid pressure brake, the combination with a brake pipe, of asanding reservoir, a variable load mechanism operable by fluid underpressure, a fluid pressure operated relay valve device for supplyingfluid under pressure to said variable load mechanism, means operatedupon a reduction in brake pipe pressure for supplying fluid underpressure from said reservoir to said relay valve device, and meansassociated with said rela valve device operated upon a reduction insanding reservoir pressure for closing oil? the supply of fluid underpressure to said variable load mechanism.

11. In a fluid pressure brake, the combination with a variable loadmechanism operable by fluid under pressure for effecting an applicationof the brakes varying in accordance with the load on the car, of a relayvalve device for supplying fluid under pressure to said variable loadmechanism in eflecting an emergency application of the brakes, and meansfor automatically closing oil the supply of fluid to said variable loadmechanism when the ei'l'lergency application ot the brakes has beeneflected.

12. In a fluid pressure brake, the combination with a variable loadmechanism operable by fluid under pressure for eflecting an applicationof the brakes varying in accordance With the load on the car, of a relay"alve device for supplying fluid under pressure to said, variable loadmechanism, a sanding reservoir, a valve included in said relay valvedevice, means operated upon eii'eeting an emergency application of thebrakes for supplying fluid under pressure from said sanding reservoir tosand relay valve device for opening said valve, and means forclosing-said valve upon a reduc tion in sanding reservoir pressure.

13. In a fluid pressure brake, the combination with a brake pipe, of aVariable load mechanism operai'ed by fluid under pressure, and a relavvalve device adapted to control the eupplv of fluid under pressure tosaid variable load mechanism, said relay valve device having a chamberconneci'ed with said brake pipe and having a communicating chamberconnected with said variable load mechanism, a valve for controlling thecommunication between said chambers, means for holding said valvenormally closed, and means For opening said valve upon effecting anemergency application of the brakes.

1.4. In a fluid pressure brake, the combination with a brake pipe, of avarialiile load mechanism operated by fluid under pressure, and a relayalve device adapted to control the supply of fluid under pressure tosaid variable load mechanism. said relay valve device having a chamberconnected with said brake pipe and having a comuumicating chamberconnected with said variable loud lnoclumism, a valve for controllingthe c0mmunicaiiiou between said chambers, a spring for holding: saidvalve normally closed, and fluid pressure operated means :Ior openingsaid valve upon rile-cling! an emergency applical'iou oi the brakes.

In testimony whereof I have hereunto set my hand.

JOSEPH M. DAPRON.

